Citadel

Citadel is a type of Sen Totally Towers there are Citadels in all realms

Citadels in every realms:

Realm 1:

Citadel of Volcano Covering

Realm 2:

Citadel of Wicked Strategy Collaborations

Realm 3:

Citadel of Astronomy

Realm, 4:  (NOT CONFIRMED)

Citadel of Cyan Design